The present invention is a radically curable organosiloxane graft polyvinyl alcohol polymer having structural units represented by both of the following general formula (1) and general formula (2). The present invention provides a radically curable organosiloxane graft polyvinyl alcohol polymer having general properties such as film-forming property and transparency, excellent handleability as a liquid material since solubility in an organic solvent is high, and both of solvent resistance and moldability of the obtained film.